The present invention relates to data processing by digital computer, and more particularly to tunable object detection.
An optical curtain generating device typically includes a light emitting pillar assembly accommodating an array of light emitting units within a pillar case and a light receiving pillar assembly accommodating an array of light receiving units within a pillar case, the light emitting pillar assembly and light receiving pillar assembly being placed opposite each other so as to form a light curtain for detecting an object between the pillar assemblies.
The arrays of light receiving and emitting units accommodated in the pillar cases are typically formed by combining a number of multi-beam optical modules each having a unit number of light beams, such as, for example, four, eight and sixteen light beams. Each multi-beam optical module includes a number of optical elements, such as a light emitting element and a light receiving element in the example of a light receiving unit, corresponding to a unit number of light beams that could be focused by addition of optical lenses, which are integrally incorporated in front of emitting and receiving units that fixes a pitch of the light beams.
There are a number of applications in which a moving object is detected using a light curtain. Among these applications, there are applications that are aimed to prevent unauthorized activities, such as detection of an object that is not expected. The intensity and/or accuracy of detection can vary.
There are number of applications that do not require high intensity or high accuracy of object detection that high cost security systems offer, but rather require an object detection system that serves as a deterrent system or device aimed at improving business performance, e.g., an object detection system installed for automatic check out lines in supermarkets and other stores with an objective to detect other objects, if any, in addition to the objects that are expected, i.e., purchased objects. Due to a variety of object sizes and their dollar value, there is no need for a business to use a high cost security type object detection system. Instead, a low cost object detection system can be used as a deterrent device to assist business management of a store in reducing loss of revenues in a form of valuables for which they were not paid. The deterrent type object detection system can be classified by its ability to detect illegal or invalid activities, such as, for example, the presence of objects not expected or the presence of more objects than expected. The performance of these types of systems can be characterized by parameter detection intensity.